from __future__ import division

def jia(x,y):
    return x + y

def jian(x,y):
    return x - y

def cheng(x,y):
    return x * y

def chu(x,y):
    return x / y

op = {"+" : jia, '-': jian,'*': cheng,'/':chu}

print  op['+'](1 , 2)
